Influencia de algunas variables en el ensayo a compresión de probetas testigo en un hormigón autocompactante

La estimación de la resistencia a compresión a través de la evaluación de probetas testigo depende de numerosas variables, entre ellas, el diámetro de la probeta testigo, la dirección de extracción en relación con la dirección del hormigonado, el estado de humedad de la probeta testigo en el momento de ser ensayada, la esbeltez de la probeta testigo, la armadura embebida en la probeta testigo y la edad del hormigón investigado. El objetivo de este trabajo experimental ha sido evaluar, para un hormigón autocompactante, el efecto que presentan algunas de estas variables en el resultado de la resistencia a compresión de las probetas testigo. Estos efectos pueden ser muy diferentes de los que ocurren en el hormigón vibrado, debido a que no existe en este caso un procedimiento específico para la compactación de las probetas moldeadas. Igualmente se han analizado los posibles factores de corrección utilizados en la estimación de la resistencia a compresión de la probeta moldeada a través de la resistencia a compresión de la probeta testigo. Para ello se han fabricado 30 bloques de 50x50x100 cm en HAC cubriendo un amplio rango de resistencias (20 MPa - 80 MPa), de los cuales se extrajeron un total de 360 probetas testigo. Paralelamente a la ejecución de los bloques se han fabricado 90 probetas cilíndricas de 15 30 cm que posteriormente fueron ensayadas a compresión a la misma edad que las probetas testigo (28 días). Los resultados muestran que algunas de las variables incíden de forma muy diferente en estos hormigones que en los hormigones convencionales, en especial la dirección de extracción y el coeficiente de paso para considerar la resistencia en probeta moldeada

First Report of Soybean Vein Necrosis Disease Caused by Soybean vein necrosis-associated virus in Wisconsin and Iowa

Several viral diseases of soybean (Glycine max) have been identified in the north-central U.S. soybean production area, which includes Wisconsin and Iowa (2). Previously, Soybean vein necrosis disease (SVND) caused by Soybean vein necrosis-associated virus was reported in Arkansas, Tennessee, and other southern states (4). In September 2012, soybean plants with symptoms similar to those reported for SVND (4) were observed in fields across Wisconsin and Iowa. Symptoms included leaf-vein and leaf chlorosis, followed by necrosis of the leaf veins and eventually necrosis of the entire leaf. Six samples with symptoms indicative of SVNaV were collected from research plots located at the West Madison Agricultural Research Station located in Madison, WI. An additional three samples were collected from three locations in central Iowa. Total RNA extracted from each sample using the Trizol Plus RNA purification kit (Invitrogen, Carlsbad, CA) was used to generate complementary DNA (cDNA) using the iScript cDNA synthesis kit (Bio-Rad Laboratories, Hercules, CA) following the manufacturers\u27 suggested protocols. The resulting cDNA was used as template in a PCR with SVNaV-specific primers, SVNaV-f1 and SVNaV-r1 (3). PCRs of two of the six Wisconsin samples and two Iowa samples were positive. Amplification products were not detected in the other five samples. The amplification products from the four strongly positive samples were purified using the Wizard SV Gel and PCR Purification Kit (Promega, Madison, WI) following the manufacturer\u27s suggested protocol and were subjected to automated sequencing (University of Wisconsin Biotechnology Center or Iowa State University, DNA Sequencing Facilities). BLASTn (1) alignments of the 915-bp consensus sequence revealed 98% and \u3e99% identity of the Wisconsin and Iowa samples, respectively, with the ‘S’ segment of the SVNaV ‘TN’ isolate (GenBank Accession No. GU722319.1). Samples from the same leaf tissue used above, were subjected to serological tests for SVNaV using antigen coated-indirect ELISA (3). Asymptomatic soybeans grown in the greenhouse were used as a source of leaves for negative controls. These tests confirmed the presence of SVNaV in eight symptomatic soybean leaflets collected in Wisconsin and Iowa. The asymptomatic control and one Iowa sample, which was also PCR-negative, were also negative by serological testing. Six additional samples from soybean fields in as many Wisconsin counties (Fond Du Lac, Grant, Green, Juneau, Richland, Rock) tested positive for SVNaV using specific primers that amplify the ‘L’ segment (4). The sequenced amplification products (297-bp) showed 99 to 100% homology to the L segment of the TN isolate (GU722317.1). To our knowledge, this is the first report of SVNaV associated with soybean and the first report of SVND in Wisconsin and Iowa. Considering that little is known about SVNaV, it is assumed that it is like other Tospoviruses and can cause significant yield loss (4). Soybean is a major cash crop for Wisconsin and Iowa, and infection by SVNaV could result in potential yield loss in years where epidemics begin early and at a high initial inoculum level

Seguimiento del Grado en Geología (Facultad de Ciencias, Universidad de Alicante, curso 2015-16)

La Facultad de Ciencias de la Universidad de Alicante ha constituido una red de trabajo formada por los profesores coordinadores de semestre del Grado en Geología, así como por los coordinadores responsables de la titulación. Los objetivos de esta red son: Asegurar la ejecución efectiva de las enseñanzas conforme al contenido del plan de estudios del título verificado; detectar posibles deficiencias en su implementación, proponiendo recomendaciones y sugerencias de mejora; y evidenciar los progresos en el desarrollo del Sistema de Garantía Interno de Calidad (SGIC) tanto en lo relativo a la revisión de la aplicación del plan de estudios como a la propuesta de acciones para mejorar su diseño en la implantación. El método de trabajo se basa en reuniones en las que los miembros de la red plantearán y debatirán los parámetros e indicadores de seguimiento de la red. Cada coordinador llevará a cabo una investigación individualizada del semestre del que es responsable en coordinación con los miembros de su comisión. Asimismo, se participará en la elaboración de los informes de autoevaluación del título

Organizing health care: an ethical perspective

Indexación: Web of Science; Scielo.Health Care at population level is a complex problem. Having this in mind, the purpose of this paper is to focus on the goods that are ethically relevant in the process of caring for health at this level. We briefly analyze some of the Chilean health statistics that, although they show important improvements along the years, demonstrate that certain conditions are to be deemed as inadequate by both healthcare providers and patients. Ethics is a central component to determine how to structure and organize health care systems and how they should operate. We emphasize Human Dignity as an ethical corner stone of the Health Care System, along with other important values such as Justice and Humanization, under the scope of the Ends of Medicine, and other components such as technical competence of providers and the financing of the whole process. We conclude that as far as a health care system is organized in a way that medical practice is well ordered, primarily and fundamentally according the Ends of Medicine and the good of persons, such a health care system is ethically adequate.http://ref.scielo.org/9bt3z

Evaluación de la sacarificación de yuca mediante el proceso convencional y el proceso low-energy, para su posterior determinación de la cinética de reacción

En este trabajo se evaluaron los ensayos para la obtención de azúcares fermentables a partir de materias amiláceas, en este caso particular yuca, los cuales comprendieron el seguimiento de la reacción de hidrólisis enzimática para la posterior determinación de la cinética de reacción (formación de producto en función del tiempo). En una primera etapa se consideró el proceso convencional que consta de licuefacción y sacarificación, a cargo de una alfa-amilasa y una gluco-amilasa comerciales respectivamente. Yen una segunda etapa la acción bifuncional de una única enzima comercial, analizándose por separado las dos partes constitutivas de la yuca: el parénquima interno y el parénquima externo. La materia prima se caracterizó en cuanto a su composición, porcentaje de humedad, proteína y por último contenido de almidón enbase seca.This work evaluated the attempts to obtaining fermentable sugars took from starchy materials; in this particular case starch, which cover the tracing of the reaction of enzymatic hydrolysis for the subsequent determination of the kinetic reaction (formation of product in function of time); the first step considered the conventional process that consists in liquefaction and saccharification, in uncharged to a commercial alpha-amylase and gluco-amylase respectively, the second step was the action bi-functional by only one commercial enzyme, this was analyzed separating the two constitutive parts of the starch: the inside parenchyma and the extern parenchyma. Finally the raw material was distinguished as far as its composition, moistness percent, protein and for last contend of starch in dry low

MODIFICACIÓN DE UN CONFLICTO SEMIÓTICO EN UN AMBIENTE DE TRABAJO COLABORATIVO

En este escrito se presenta un análisis de la actividad matemática realizada por dos estudiantesen un curso de Didáctica de la Variación del programa de Licenciatura en Educación Básicacon Énfasis en Matemáticas de la Universidad Distrital Francisco José de caldas- Bogotá,para describir y analizar el uso del registro algebraico alfanumérico al resolver un problema demodelación relacionado con la función lineal cuando participaron en un entorno deaprendizaje que promueve el trabajo colaborativo. El análisis reporta evidencia de la presenciade conflictos semióticos y de la modificación de un conflicto interaccional en un conflictocognitivo. Este análisis permite caracterizar la emergencia de los conflictos semióticos y cómoson manejados por las estudiantes, aportando información útil para comprender los procesosde aprendizaje de los estudiantes para profesor de matemáticas, en un contexto de aula en elque se adopta la resolución de problemas.Palabras clave: registro algebraico, conflicto semiótico, trabajo colaborativo.MODIFICATION OF CONFLICT SEMIOTICIN A COLLABORATIVE WORK ENVIRONMENTAbstractThis paper presents an analysis of mathematical activity developed by two students in a courseon Didactic of Variation which belongs to the Program of Teachers Formation in BasicEducation with Emphasis in Mathematics from the Universidad Distrital Francisco José deCaldas, Bogotá. It describes and analyzes the use that those students did about alphanumericalgebraic register to solve a modeling problem related to the linear function when they wereinvolved in a learning environment that promotes collaborative work. The analysis evidencethe presence of semiotic conflicts and the change from interactional conflict into a cognitiveconflict. This analysis allows characterizing the semiotic conflicts emergence and how theyare handled by the students, providing useful information for understanding the learningprocesses of students trying to become a mathematics teacher in a classroom context in whichthe solving of problems is adopted

Respecting patient intimacy

Indexación: Web of Science; Scielo.Transparency as a general rule for all our professional acts casts doubts about the statement of the Hippocratic Oath that says "Whatever I see or hear in the lives of my patients, I will keep secret, as considering all such things to be private". Medical secrecy protects the intimacy of patients, who reveal to their physicians their most hidden secrets aiming to recover their health. Therefore, physicians should receive those secrets with reverence and care, as servers and not as their owners. The values associated with the respect for personal intimacy are the anthropological basis of medical confidentiality. A medical act is performed by definition between two equally honorable individuals. Therefore, the professional honors the trust of his patient, maintaining strict confidence of what is revealed. Therefore, medical secrecy must be strengthened rather than weakened, pursuing common wealth and dignity.http://ref.scielo.org/cf3mx

First Records for Spawning of Caribbean Acropora Species in Colombian MPAs

Estimates of Colombian Caribbean coral percent cover in the Southern Caribbean are consistent with those throughout the Caribbean Sea, which has declined to about 10% of historical levels in the last few decades. Human activities like destructive fishing techniques in the marine parks have degraded the reefs over the last few decades. Colombia’s Marine Protected Areas (MPAs) have thousands of square kilometers to map and patrol and few resources to devote to scientific and restoration efforts. Efforts to implement sexual reproduction techniques for restoration are starting to successfully propagate and settle corals on ceramic plates for reef deployment in the area but require more natural history information for large-scale implementation in restoration. Past observations of captive endangered coral Acropora cervicornis in the nursery of the Oceanario Islas del Rosario indicate spawning 6 days after the August full moon for the previous 3 years. Coral spawn collection from the wild reef was completed each night from 2 to 7 days after the full moon in August 2019, and resulted in the first observation of A. cervicornis spawning on natural reefs in Parque Nacional Natural Los Corales del Rosario y de San Bernardo, a 1,200 km2 underwater national park and MPA established in 1977. Additionally, coral spawn collection from the nursery reefs in August 2019 provide the first reported observations of spawning for endangered coral Acropora palmata in Colombia